COLLEGE STATION, Texas – Projections indicate that hatchability rates for broilers could decrease to approximately 60 percent by 2050 without corrective action, a new analysis conducted by the Department of Poultry Science at Texas A&M University finds.

Historically, fertility has been one of the main drivers of how the broiler industry has grown, said Giri Athrey, associate professor at Texas A&M.

“(Fertility) has been a concern and something people have studied intensively since the 1980s,” he said. “Infertility has been more of a recent incidence, I would say, in the last 25 years. I think you start seeing in the (research) literature different concerns voiced about it in the last two decades.”

Several decades ago, most fertility research focused on characterizing fertility traits and optimizing fertility management. As demand for poultry products increased over the years, the industry improved its ability to produce large birds rapidly through selective breeding.

However, chicken infertility made headlines in 2014. Aviagen Group, a global poultry breeding company that develops pedigree lines for broiler chickens and turkeys, reported that it had discovered a key breed of rooster, the standard Ross male, had a genetic issue that reduced its fertility. Reuters reported that the company acknowledged a change to the breeds’ genetics made the birds sensitive to being overfed, which may have led to decreased fertility. Seventeen percent of Aviagen hens failed to hatch chicks, up from its previously reported 15 percent.

In the months following the announcement, U.S. poultry prices reached record-high levels. At the time, Ross male birds were the sires of about 25 percent of the chickens consumed in America. Aviagen Group responded to the issue by replacing the Ross male with a different breed, and the issue quietly resolved itself without much fanfare.

While management tweaks and patchwork solutions seem to have cleared up infertility issues, they’ve never really gone away, Athrey said. The goal of the research group’s analysis was to establish a baseline for the infertility issue, as there has been no published research quantifying the extent of the problem.

The group utilized data available through the USDA’s National Agricultural Statistics Service to examine historical patterns of fertility nationwide from 2013 to 2022. The emerging patterns weren’t promising; if no serious interventions are forthcoming, fertility will continue in a downward trajectory, Athrey said.

There is no one answer as to why fertility is declining. Fertility is a multifactorial trait with many genetic and environmental factors influencing it. There are physiological attributes that contribute to fertility, like body weight, that can be maintained by management practices. Still, selecting birds for those attributes alone wouldn’t make up for the deficit in fertility, Athrey said. Additionally, genetically selecting for increased fertility would prove difficult because fertility traits have low heritability.

“Management alone is not the biggest determinant of this problem,” Athrey said. “When we see a problem of this scale, I think it’s for everybody to understand that this is not one of those things where you can just optimize something and obtain a one percent increase and think you have a solution. This is a much bigger problem.”

Many groups of researchers will need to come together to help solve this problem, including geneticists, nutritionists and animal welfare researchers, Athrey added. His group has been investigating various male fertility aspects, such as semen motility, sperm morphology, and the reproductive microbiomes of males and females.

Other researchers have been investigating avenues toward maintaining and increasing fertility. Such practices include spiking, a technique used to enhance flock fertility by replacing older males with younger ones, regulating feed intake, and providing dietary supplementation.

“What I would really love to do is talk to people who are also thinking about (infertility) from other perspectives, like nutrition and management, and develop a program where we could figure out this multifactorial problem,” Athrey said.